Given a locally compact abelian group $G$ with Haar measure $m$, it is well-known that there exist measures $\mu\in M(G)$ which are singular (with respect to $m$), but the convolution product $\mu\ast\mu$ is absolutely continuous. Is there any condition characterizing the measures $\mu$ which satisfy the following (opposite) $tauberian$ property: given $\nu \in M(G)$, $\mu\ast\nu$ absolutely continuous implies $\nu$ absolutely continuous?